EP0222807A1

EP0222807A1 - Replacement aerial

Info

Publication number: EP0222807A1
Application number: EP19860902873
Authority: EP
Inventors: Robert Latimer Glover
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-05-07
Filing date: 1986-05-07
Publication date: 1987-05-27
Also published as: GB8700137D0; GB2188492A; WO1986006880A1

Abstract

Antenne de remplacement pour automobile comprenant un élément d'antenne (1) monté sur un dispositif de connexion(20, 22) qui s'engage dans l'emboîture restante (11) d'une ancienne antenne cassée. L'antenne est fixée par rotation relative de deux éléments, afin de former un élément conique (27) destiné à écarter un tube fendu (30), l'antenne trouvant ainsi prise à l'intérieur de l'emboîture.Replacement antenna for automobile comprising an antenna element (1) mounted on a connection device (20, 22) which engages in the remaining socket (11) of an old broken antenna. The antenna is fixed by relative rotation of two elements, in order to form a conical element (27) intended to separate a split tube (30), the antenna thus finding taken inside the socket.

Description

REPLACEMENT AERIAL

Th i s i nvent ion r ela te s to a r epl acemen t ae r i a l , particularly for automobiles and like vehicles .

Today it is not uncommon for aerials on vehicles to be vandalised if left in their extended condition. This usually results in an aerial being broken off close to its base, making the aerial unusable and irreparable. The only remedy at present is to replace the aerial in toto. This is often a difficult operation, necessitating as it does, the threading of a permanently attached lead through various bulkheads to a position behind the radio.

The present invention seeks to enable the repair of telescopic and other aerials having similar fixings without the necessity of removing the old broken aerial.

Replacement aerials are already known which consist of an aerial mast connected to a cylindrical socket member. Two grub screws are arranged in the wall of the socket member on diameters at right angles. This socket member can be placed over the projecting stub of a previous aerial and the screws tightened. However problems often arise because either the stub is bent and cannot be straightened, or because there is no stub left at all. There has then been no alternative to fitting a completely new aerial.

According to the invention, there is provided a replacement aerial for attachment in place of a broken aerial on a vehicle, having an aerial element mounted on connection means which engage the remains of the broken aerial, wherein the connection means comprises insertion means which enter an existing aerial socket and include retaining means which can be expanded to retain the connection means in the aerial socket.

Preferably the insertion means and the associated engagement means are detachable from the aerial element to enable replacement of the insertion and engagement means with means associated with different socket sizes.

The aerial socket may comprise the base part of an existing aerial left when the original aerial itself has become broken.

The engagement means may comprise an expandable sleeve on the insertion means and the insertion means may be attachable to and detachable from the aerial element by a screw and socket connection.

The aerial element may comprise a glass fibre or rubber rod rendered suitably conducting.

The invention will now be described in greater detail, by way of example, with reference to the drawings, in which :

Figure 1 shows a sectional view of a replacement aerial according to the invention installed in the existing base of a broken aerial;

Figure 2 shows a modified form of insertion and engagement means; and

Figure 3 shows a modified form of the embodiment of Fig.2. Referring to Figure 1, a replacement aerial comprises a glass fibre rod 1 suitably rendered conducting. It is of a suitable length for the desired radio reception, and may be resilient to prevent it being broken off. It may be freestanding or connected at the other end to the vehicle body as required.

At the base end 2 of the rod 1, it is bored and threaded at 3, suitably using an insert to take an expanding connector 4.

The existing base 5 is only shown in part. The part shown comprises a rubber washer 6 which is in engagement with the car body 7, a dome member 8 sitting on the washer 6, the main retaining part 9 of the base and the tightening nut 10. Beneath the car body 7 is a part 11, shown only diagrammatically, which indicates the remaining part of the telescopic structure.

The expanding connection 4, which forms both insertion and engagement means, comprises a central rod 12, suitably of steel having a wedge like portion 14 at one end and a threaded portion 15 at the other end which mates with the threaded socket 3 on the glass fibre rod 1. Around the rod 12 is an expanding sleeve 17 suitably of brass, having slots (not shown) in its lower end to allow it to expand under the action of the wedge like portion 14. Flats (not shown) are provided at the upper end of the sleeve 17 and the lower part of the rod 1 for a purpose to be described.

The operation of replacing or repairing an existing broken aerial using the above described replacement will now be considered. Using a screw driver or similar implement, the remaining part of the broken off telescopic element is pushed downwards into the part 11 leaving the bore of the main retaining part 9 free. A connector 4 of appropriate diameter is inserted into the bore of the main retaining part 9 until about 1/8 inch of the sleeve 17 is proud of the bore.

The glass fibre rod aerial 1 is then screwed by its socket 3 on to the threaded portion 15 of the rod 12. Using two spanners, one on the flats of the rod aerial 1 and the other on the flats of the sleeve 17, the rod 12 is drawn up, expanding the sleeve 17 by engagement of the wedge like portion 14, into tight engagement with the inner walls of the bore of the main retaining part 9 so as to retain the aerial.rod 1 and provide a good electrical connection.

Once this tightening up has been achieved, the sleeve 17 and rod 12 will be wedged in place and the aerial rod 1 can then be removed when desired, for example when going through a car wash, without disturbing the fixing.

While the rod aerial 1 is virtually indestructable, should it ever become damaged, a new rod can easily be screwed in its place.

It will be appreciated that various modifications can be made to the above described embodiment without departing from the scope of the invention. For example, the connector could be entirely self contained if the threaded part of the rod is provided with a screw driver slot and the upper end of the sleeve is threaded. The replacement aerial is suitably sold as a kit which includes a number of connectors 4 covering the usual range of sizes necessary. Different lengths or types of aerial rods may be used, e.g. short straight aerials or whip type aerials which may be attached to the vehicle at their free end in a well known way.

In order to make the adaptor section more universal, a modified version shown in Figure 2 or Figure 3 may be used. This is to a larger scale than Figure 1.

The adaptor shown in Figure 2 is in three sections, shown on the attached drawing as 20, 21 and 22.

Section 20 is of mild steel. It has a partially threaded central bore 23 to accommodate section 21 and a top external 5 mm thread 24 to which the aerial 1 is fixed. It is constructed with a hexagonal bar section

25 which is 12 mm diameter across the flat surfaces, thus taking a 12 mm metric spanner. The bevelling at

26 means that the adaptor will always centralise in an aerial hole of any diameter. A tapered end 27 enters into section 22 and performs the same function as wedge 14 in Figure 1.

Section 21 is a steel rod threaded at both ends.

The bottom end is screwed permanently into section 22.

At the top it has a screwdriver slot 28.

Section 22 is made of mild brass. A split and bored conical section 30 has the function of sleeve 17 in Figure 1. The bore 31 is slightly widened at 32 to facilitate the easy entry of tapered end 27 of section 20. Since contact points are deep inside some aerials, a rounded extension 33 is provided having a length of about 4cms. When the adaptor is inserted into the hole of a remaining aerial base, the slot 28 is proud of the top of section 20. A small screwdriver is placed in the slot. A 12 mm spanner is used on the hexagonal bar sec'tion 25 in a clockwise direction while keeping^' the steel bar immobile with the screwdriver and thus preventing section 22 from rotating. (Were it to rotate, tightening would be precluded.) Tapered end 27 will enter the top of bore 31. The further it is screwed down into section 22 the greater the expansion of the brass section 30 will be.

The diameter of the section 30 is 6 mm; in tests it has expanded to 12 mm without the brass shearing at its neck. Once it has expanded to contact and lock into the internal wall of the aerial hole, section 20 is drawn downwards to seat firmly at bevelling 26. The screwdriver and spanner are then removed and the replacement aerial is screwed on to the 5 mm threat 24 at the top.

This form of adaptor can be made overall of smaller diameter than that in Figure 1, and therefore can be of more uniform application. In addition, the extension 33 can be as long as is reguired to meet the metal contact which is sometimes relatively deep inside an otherwise plastic aerial tube.

Figure 3 illustrates a further improved replacement aerial. This again is in three sections 20, 21 and 22. In this instance, instead of an external thread 24 serving to attach the aerial mast (not shown), a threaded bush 40 forms part of the mast, and is held on an unthreaded stub 41 by means of a split ring 42. The bush cannot be removed from the mast after assembly except by use of a special tool, but can rotate. The bush 40 is also tapped at 43 to receive the top end of threaded rod 21. Moreover, the stub 41 and the remainder of section 20 has a bore which is of larger diameter than the rod 21, so that section 20 can slide along the rod. The rod has a groove 44 along its length into which engages an inwardly projecting lug or pin 45 of the section 20. It can thus be seen that if the rod

21 is held stationary the whole assembly of aerial mast, bush 40 and section 20 can be moved lengthwise of the rod by gripping and rotating the aerial mast itself.

Section 20 has a reduced diameter portion 46 which terminates with the tapered conical end surface 27. The diameter of portion 46 is the same as that, of section

22 so that it can be inserted into an aerial socket of the smallest diameter that will also accept section 22. A conically tapered sleeve 47 of larger diameter is provided for reasons to be explained, but is removable by sliding over section 22.

Section 22 is of reduced diameter compared with Figure 2, but otherwise of similar form. It has a diameter of about 5 mm over its whole length.

The operation differs sl ightly from that in Fig.2. The aer ial i s suppl ied w i th the aer ial mast assembled on the inser tion means , and sleeve 47 removed. The insertion means is inserted into the aer ial socket .

A spanner is used to hold section 20 , and wi th i t sections 21 and 22. The mast is then rotated by hand to force the tapered end 27 downwards into the top of he bore in sect ion 22. Thi s cause s expans ion of the top par t 30 wh ich eng ages and g r ips in the aer ial socket. Thereafter, the spanner may not be necessary as the aerial is turned further by hand to tighten the grip in the socket. In fact, even at the start, a spanner may not be necessary if by hand the section 20 can be held sufficiently tightly to obtain the initial grip in the socket. In any event, no additional screwdriver is required as for Fig.2.

If the socket has a larger diameter between, say, 8 and 12 mm, the spread of the top part 30 required may be so great that the tapered end 27 does not impart sufficient rigidity to the fixing. In that case, the sleeve 47 may be left on and the part 30 expanded slightly to retain it before it is inserted in the socket. When fully expanded, part 30 then has the full length of the conical surface of 27 and 47 to support it. This in fact provides the necessary rigidity which is lacking if sleeve 47 is not used.

By this means, a single size of insertion means can be used to provide an effective grip in all currently manufactured aerials, which have a diameter between 5 and 12 mm.

The replacement aerials of the invention may be used to replace other types of aerials other than telescopic, if the remains of the damaged aerial provides a suitable bore into which the connector can be inserted.

From the above it will be seen that the described embodiment provides an aerial replacement, particularly for damaged telescopic aerials, which can be fitted with a minimum effort and in a short time.

Claims

1. A replacement aerial for attachment in place of a broken aerial on a vehicle, having an aerial element mounted on connection means which engage the remains of the broken aerial, wherein the connection means comprises insertion means which enter an existing aerial socket (11) and include retaining means (14,17; 27,30) which can be expanded to retain the connection means in the aerial so.cket (11).

2. A replacement aerial as claimed in claim 1 wherein the retaining means (14,17; 27,30) operates by drawing together a tapered member (14,27) and a split sleeve (17,30) whereby the latter expands to grip the inside of the aerial socket (11) .

3. A replacement aerial as claimed in claim 2 wherein said drawing together operates by contr a-rotation of members directly or indirectly in threaded engagement.

4. A replacement aerial as claimed in claim 3 wherein the connection means has an upper part (20) carrying the tapered member (14,27), a threaded centre rod (21), and a connector member (22) carrying the split sleeve (17,30) fixed on the bottom of the rod (21).

5. A replacement aerial as claimed in claim 4 wherein the top of the rod (21) has a screw-driver slot (28) and the upper part (20) has a faceted external surface to enable said contra-rotation.

6. A replacement aerial as claimed in claim 4 wherein the upper part (20) can move longitudinally of, but not rotate relative to, the centre rod (21), and wherein the contra-rotation is achieved by rotation of the bottom (40) of the aerial element relative to the upper part (20) .

7. A replacement aerial as claimed in claim 4,5 or 6 wherein the connector member (22) is elongated to project into the aerial socket (11) for the purpose of making electrical contact within the socket.

8. A replacement aerial as claimed in claim 4 wherein the effective diameter of the tapered member (14,27) can be enlarged by use of an extra sleeve member (47) having a tapered end surface, so as to adapt the retaining means to an aerial socket (11) of larger internal diameter.

9. A replacement aerial as claimed in any preceding claim wherein the aerial element is detachably mounted on the connection means and can be removed therefrom after the aerial is mounted on a vehicle.